ModuleAPI: provide method to resolve room_alias to room_id

[uriesk]

I am writing a pluggable module that joins rooms on login,
and i resolve room alias to id with:

    async def translate_room_aliases_to_ids(
        self,
        room_aliases: List[str],
    ) -> List[str]:
        room_ids = []
        logger.info('Translating room_aliases to ids')
        for alias in room_aliases:
            aliasObject = RoomAlias.from_string(alias)
            room = await self.api._store.get_association_from_room_alias(aliasObject)
            if room is not None:
                logger.info('Map alias %s to room %s', alias, room.room_id)
                room_ids.append(room.room_id)
        return room_ids;

Which isn't great, because i go through api._store.
Would be nice to have such a functionality in the api itself.

[babolivier]

also a method to set email / threepids would be nice, this is what i am using now

This method will probably be implemented separately to the one you're initially requesting, could you make a separate issue about it so it's better tracked please?

[uriesk]

of course, #13402

[buffless-matt]

@uriesk

I coincidentally have a present need for this as well 😄

I'm not sure DirectoryWorkerStore.get_association_from_room_alias would be appropriate to use for this new module API method and instead I think RoomMemberHandler.lookup_room_alias would be more appropriate because:

• It handles both local and non-local/federated rooms.
• It also queries appservices to try and do the translation.

The method could be accessed (in this new module API method) via self._hs.get_room_member_handler().

[buffless-matt]

This was completed in #13428, so this issue can be closed.